This invention relates generally to computer peripherals, and more particularly to digital mass storage devices having removable storage media.
Computer systems and other digital processing systems often include digital memory "peripherals" used for the mass storage of data, Examples of such digital memory peripherals include hard disk drives, floppy disk drives, optical disk drives, and Personal Computer Memory Card International Association (PCMCIA) cards or devices (also referred to as PC Cards) or other types "flash" memory cards. With some of these peripherals, the storage medium is permanently housed within and forms a part of the peripheral. An example of digital storage peripheral which does not allow the removal of its storage medium is a standard Winchester-type hard disk drive. Other memory peripherals allow the removal and replacement of the digital media. Examples of such peripherals include floppy disk drives and PCMCIA peripheral units.
For most types of storage peripherals with removable media, the media is manually inserted into a slot against spring pressure until a latching mechanism is engaged. In many types of such peripheral units, the media is disengaged from the unit by manually depressing a release button or lever to release the latch and thereby allow the compressed spring to partially eject the storage medium. A protruding end of the medium is then removed from the peripheral unit by hand.
In some computer systems, notably the Macintosh.RTM. computer system made by Apple Computer, Inc. of Cupertino, Calif., removable storage media can be automatically ejected by the computer system. More particularly, the Macintosh operating system can cause motors or electrical solenoids of the floppy drive unit to automatically eject a floppy disk.
Such automatic ejection of storage media has several advantages. For one, the computer can prevent the ejection of a floppy disk from the floppy disk drive if the system still needs or is processing data in conjunction with the floppy disk drive. Another advantage is that the floppy disk can be ejected automatically under certain conditions, such as during a power-down or power-up of the computer system. However, such automatic ejection systems have the disadvantage of increasing the cost of the floppy disk drive in that motors or solenoids must be provided, along with their attendant control circuitry.
An increasingly popular form of removable media is the PCMCIA memory card, which is typically a form of "flash" memory. As is well known to those skilled in the art, flash memory is form of non-volatile, solid-state, read-write memory, and PCMCIA cards are flash memory which conform to certain industry standards. Since PCMCIA cards are, themselves, quite small, and since they do not require drive motors or the like (as the case with disk drives) the PCMCIA peripheral unit can be made quite small and lightweight. This makes PCMCIA peripheral units quite attractive for small computers, such as laptop computers, Personal Digital Assistants (PDAs) such at the Newton.RTM. PDA, and other small, portable devices utilizing digital processors.
PCMCIA cards can be of other types than the aforementioned flash memory type. For example, there are PCMCIA cards which employ Static Random Access Memory (SRAM) and PCMCIA cards that are miniature hard disk drives. In addition, PCMCIA cards can include modem, cellular pager, and networking capabilities. The PCMCIA format is therefore quite flexible and is rapidly growing in popularity.
For a variety of reasons, in the past, PCMCIA peripheral units only permitted the manual ejection of the PCMCIA cards . For one, the addition of motors or solenoids to eject the PCMCIA card would substantially increase the size of the PCMCIA peripheral unit, which is considered very undesirable. For another, the motor or solenoid would add a significant cost to the PCMCIA peripheral unit.